1. Dewatering Equipment

2. Enabling Objectives:
Identify the capabilities and uses of installed drainage
Identify the capabilities and uses of portable dewatering equipment
Rig and use a peri-jet eductor to dewater a flooded compartment.
Note: All objectives are in accordance with NSTM 079 Vol. 2, NWP , COMNAVSURFPACINST B, COMNAVSURFLANTINST C, NSTM Chapter 555, NSTM 079 Vol. 3

3. Drainage and Flushing Systems
Definition: Systems of piping onboard ships, with or without plumbing facilities, installed for removing waste and flooding water from within the hull.

4. Principle Drainage Systems:
Main drainage
Secondary drainage
Plumbing and deck drains

5. Main drainage Serves all main machinery spaces
Note: On some ships, it may extend forward and aft of the machinery compartment.
Drains machinery space bilges
Drains floodable voids
Drains fuel tanks ballasted with sea water

6. Main drainage (cont.) Pumps Steam driven reciprocating (older ships)
Turbine or motor driven centrifugal
Eductors (jet pumps)

7. Secondary drainage
Drains spaces forward and aft of the main machinery spaces
The secondary drainage system is an independent system with it’s own pumps and eductors

8. Secondary drainage (cont.)
Pumps
Electrical motor driven centrifugal
Eductors (jet pumps)
Portable electric submersible pumps

9. Plumbing and deck drains
Provided to drain compartments within the ship by gravity. Gravity drainage piping is installed most extensively in compartments above the waterline

10. Weather deck drains
Flooding danger exists with gravity type drains. Such piping usually pierces the skin of the ship and passes through the watertight decks. As a damaged ship lists to one side or settles more deeply, water will flow back through drainage piping.

11. Overboard discharge connection
Allows for discharge of liquids through the hull of the ship
Located on the damage control deck and as close to the damage control deck as possible
Located on both port and starboard sides, and through the hull of each main transverse subdivision
Made flush with the outer hull surface

12. Overboard discharge connection (cont.)
Size and type:
Inboard end has a 4 inch female swivel hose connection attached to a 4 inch male-2 1/2 inch female swivel hose adapter coupling
A 2 1/2 inch hose cap is attached to the adapter

13. Drainage of magazines
All magazines having sprinkler systems have drainage capability
Magazines located above and adjacent to the weather deck, drain through a check valve installed in the bulkhead to the weather deck

14. Drainage of magazines (cont.)
For magazines not located adjacent to the weather deck, overboard drainage is provided through deck drains in the magazine with independent drain piping having a check valve at the shell

15. Drainage of magazines (cont.)
Magazines which cannot be drained overboard by gravity are drained by portable pumps, either through overhead access or a drain pipe installed through the bulkhead to an adjacent handling room, access, or passage. The drain pipe is installed in the bulkhead at a point close to the deck and fitted with a hose valve

16. Portable dewatering equipment

17. P-100
The P-100 pump unit is an air cooled, diesel driven, single cylinder, 10 horsepower, portable pump. It’s designed for fire fighting and dewatering
The pump is designed to provide 100 GPM at 83 PSI while lifting 20 feet. In high lift operations, it will deliver 71 GPM at 62 PSI while lifting 44 feet

18. P-100 equipment 3 inch suction hose Foot valve and strainer Wye gate
1 1/2 inch fire hose
Vari nozzle
Exhaust hose
1 1/2 inch Vita motivator

19. Portable electrical submersible pump
Either a 3 phase AC or a DC motor directly connected to a small, high speed, water cooled centrifugal pump
Designed to dewater compartments not served by installed drainage systems
Designed to pump cool fresh water / sea water
DFM, JP-5, heavy oil, and Navy distillate can be pumped safely. Refer to owners manual for pumping / cool down times

20. Sub pump capacities 200 GPM at 50 foot static head
Maximum suction lift of 20 feet
Pumps may be used in tandem to reduce the risk of pump damage and to increase suction lift
Energize lowest pump first

21. Sub pump safety precautions
Operator must wear 7500 volt gloves when energizing pump.
Use the double braided nylon rope to raise and lower the pump. NEVER use the electical cord!!
The pump can be operated safely with personnel in the space.
3 things must happen for electric shock to occur:
Motor must ground out, ground wire must be severed, personnel must physically touch the pump

22. Sub pump safety precautions (cont.)
Keep discharge hose free of kinks and sharp bends that will restrict flow. Back pressure will rupture motor seals.
Always use strainer and keep it clear of debris.
Keep suction lift and discharge head as low as possible.
Keep the suction end of the pump in water while the pump is operating.

23. Portable eductors
Used for dewatering operations which involve petroleum products or any type of fuel

24. 2 types of eductors Peri jet 1 1/2 x 2 1/2 single jet (s-type)
Both are actuated through a fire hose by firemain pressure or from the discharge a P-100 pump.

25. Eductors (cont.)
Rule of thumb: The amount of water you put into it is what you’ll pump out of the space.
Example
Water inlet to eductor is 100 GPM
Water removed from space is 100 GPM
Total discharge is 200 GPM

26. Review and summary Types of drainage Overboard discharge connections
Main drainage
Secondary drainage
Plumbing and deck drains
Overboard discharge connections
Drainage of magazines

27. Review and summary (cont.)
Emergency drainage equipment
Portable P-100 pump
Portable electric submersible pump
Portable eductors
Peri jet
S-type

28. THE END!!!